The present invention relates to a gear-shifter, and more particularly to a grip gear-shifter for being used in actuating derailleur of a bicycle.
The conventional gear-shifter used in a bicycle whish has a derailleur is actuated by the drive of different gears of the conventional gear-shifter.
In the conventional gear-shifter includes a gear, a roller chain, the front and rear gearbox, shift levers and a cable for actuating the gear-shifter. According to the motion types, the shift levers could be classified into the single-lever type, the reversal double-lever type and the grip type.
The prior art disclosed a single-lever type of gear-shifter used in a bicycle. However, the single-lever type of gear-shifter has a too broad motion range to be conveniently operated by the user. The palm of the user would be uncomfortable when the user holds the lever. In addition, the single-lever type of gear-shifter is used for positioning by using friction. Thus, the lever could not provide sufficient clasping strength to maintain the roller chain in the correctly position when the bicycle is used in a vibrated environment.
The prior art further disclosed a reversal double-lever type of the gear-shifter used in a bicycle. The reversal double-lever type of the gear-shifter could be used for precisely and stably positioning even in an adverse environment. However, the levers are connected to two mechanisms for positioning. Thus, the assembly of the levers and mechanisms are complicate and time-consuming, and certainly the fabrication cost is increased. The reversal double-lever type of gear-shifter is suitable foe being used in a high priced bicycle.
Moreover, the prior art disclosed grip type of gear-shifters having simple mechanisms for decreasing assembly time and fabrication cost. However, when the conventional grip type of gear-shifter is operated, the grip is usually overshot by the over applying force owing to the geometric limitation. In addition, the conventional grip type of gear-shifter is operated unstably, so that the skip shift is usually occurred in the bicycle used in a vibrated environment. In order to overcome the problem about skip shift, the resilient steel plate and the friction between the resilient steel plate and the notches should be provided in the gear-shifter. However, the friction between the resilient steel plate and the notches should be overcome when the bicycle is in the state of shifting gears. Thus, the resilient steel plate and the notches would be abraded.
In order to overcome the foresaid drawbacks of the conventional gear-shifters, the present invention provides a grip gear-shifter for being used in actuating a derailleur of a bicycle.
It is therefore an object of the present invention to provide a grip gear-shifter having high stability for positioning and saving labor.
It is another object of the present invention to provide a grip gear-shifter having a simple mechanism for being easily assembled.
It is another object of the present invention to provide a grip gear-shifter for reducing the fabrication cost and assembly time.
In accordance with the present invention, the grip gear-shifter for being used in actuating derailleur of a bicycle includes a return spring, a resilient steel plate having a polyhedron-formed controlling pawl, a guiding ring having a guiding notch for guiding a cable, a first module for lodging and positioning the controlling pawl when the bicycle are in the state of shifting gears, and a second module having a projection and a positioning unit for operating in coordination with the return spring and the resilient steel plate, thereby forming a relative motion of the resilient steel plate and the first module to correctly shift gears when the bicycle are in the state of shifting gears.
Preferably, the resilient steel plate is U-shaped.
The second nodule includes an operating grip having plural fixing slots for being used in operations of up-shift and down-shift, and a rubber cover for covering the operating grip handled by a user.
The operating grip includes the projection and the positioning unit for pressing the return spring to form a resilience due to the deformation.
The positioning unit comprises a positioning lump and a contacting portion.
The rubber cover has plural protruding portions for suiting the fixing slots of the operating grip to prevent the rubber cover from falling from the operating grip when the operating grip covered by the rubber cover is twisted by the user.
In addition, the first module includes a fixing main body for securing the grip gear-shifter to the bicycle, a grip-fixing element having a flange for lodging in an annular slot of the operating grip to fix the operating grip, a positioning slide having plural notches for being lodged by the controlling pawl and positioning the controlling pawl when the bicycle is in the state of shifting gears, a clamping element for suiting the fixing main body and fixing the fixing main body to a handlebar of the bicycle, and a cable timer disposed at a wound end of the cable for adjusting the tension of the cable.
The fixing main body further has a first hole and a second hole thereon for conveniently assisting windup of the cable, thereby the cable is pulled through the first hole, pushed in the guiding notch and further pulled from the second hole, wherein the second hole has external threads.
The fixing main body further includes a first cylinder and a second cylinder for respectively slipping into the guiding ring and the operating grip, a receiver for receiving the positioning slide, and a square-shaped slot for receiving the grip-fixing element.
The cable trimmer could have internal threads for screwing in coordination with the external threads of the second hole, thereby adjusting the tension of said cable.
In accordance with the present invention, the grip gear-shifter for being used in actuating derailleur of a bicycle includes a return spring, a resilient steel plate having a polyhedron-formed controlling pawl, a guiding ring having a guiding slot and a circular indent for guiding and receiving a cable, a spring slot for receiving the return spring and a guiding notch for receiving the resilient steel plate, a first module for lodging and positioning the controlling pawl when the bicycle are in the state of shifting gears, and a second module having a projection and a positioning unit for operating in coordination with the return spring and the resilient steel plate, thereby forming a relative motion of the resilient steel plate and the first module to correctly position said derailleur when said bicycle are in said state of shifting gears.
The second module includes an operating grip having plural fixing slots for being used in operations of up-shift and down-shift, and a rubber cover for covering the operating grip handled by a user.
The operating grip includes the projection and the positioning lump for pressing the return spring to form a resilience due to the deformation.
The first module includes a fixing main body for securing the grip gear-shifter to the bicycle, a grip-fixing element having a flange for lodging in an annular slot of the operating grip to fix the operating grip, a positioning slide having plural notches for being lodged by the controlling pawl and positioning the controlling pawl when said bicycle is in the state of shifting gears, a clamping element for suiting the fixing main body and fixing the fixing main body to a handlebar of the bicycle, and a cable trimmer disposed at a wound end of the cable for adjusting the tension of the cable.
In accordance with the present invention, the grip gear-shifter for being used in actuating derailleur of a bicycle includes a return spring, a resilient steel plate having a polyhedron-formed controlling pawl, a guiding ring having a guiding slot and a circular indent for guiding and receiving a cable, a spring slot for receiving the return spring and a guiding notch for receiving the resilient steel plate, an operating grip having plural fixing slots for being used in operations of up-shift and down-shift, a rubber cover for covering the operating grip handled by a user, a fixing main body for securing the grip gear-shifter to the bicycle, a grip-fixing element having a flange for lodging in an annular slot of the operating grip to fix the operating grip, a positioning slide having plural notches for being lodged by the controlling pawl and positioning the controlling pawl when the bicycle is in the state of shifting gears, a clamping element for suiting the fixing main body and fixing the fixing main body to a handlebar of the bicycle, and a cable trimmer disposed at a wound end of the cable for adjusting the tension of the cable.
In addition, the fixing main body further has a first hole and a second hole thereon for conveniently assisting windup of the cable, thereby the cable is pulled through the first hole, pushed in the guiding notch and further pulled from the second hole, wherein the second hole has external threads.
The fixing main body further includes a first cylinder and a second cylinder for respectively slipping into the guiding ring and the operating grip, a receiver for receiving the positioning slide, and a square-shaped slot for receiving the grip-fixing element.
The operating grip includes a projection and a positioning unit for pressing the return spring to form a resilience due to the deformation.
The positioning unit includes a positioning lump and a contacting portion.
The cable trimmer could have internal threads for screwing in coordination with the external threads of the second hole, thereby adjusting the tension of the cable.
The present invention may best be understood through the following descriptions with reference to the accompanying drawings, in which: